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BSD

Specialty Definition: BSD

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Specialty Definition: Apple Darwin

(From Wikipedia, the free Encyclopedia)

Darwin is the core operating system of Apple Computer's Mac OS X, and runs on the open source Darwin kernel, XNU.

Darwin integrates a number of technologies, most importantly Mach 3.0, operating-system services based on 4.4BSD (Berkeley Software Distribution, particularly FreeBSD), high-performance networking facilities, and support for multiple integrated file systems.

Originally developed at Carnegie Mellon University, the Mach kernel manages all the tasks and processes the computer runs. Apple's Head of Software Engineering, Dr Avie Tevanian, worked on the Mach kernel at Carnegie-Mellon. Mac OS X owes no small part of its existence to Avie Tevanian. The Mach kernel gives Mac OS X features such as protected memory and symmetric multiple processing.

Currently Darwin is built for both Apple's PowerPC architecture as well as to the Intel architecture, though the latter only has very limited driver support.

The Darwin developers decided to take a mascot in 2000. Hexley the platypus was chosen over other contenders, such as an Aqua Darwin fish, Clarus the DogCow, and an orca.

External links

• Apple - Mac OS X - Technologies - Darwin
• OpenDarwin community development site
• Hexley, the Darwin mascot

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Apple Darwin."

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Berkeley Software Distribution

(From Wikipedia, the free Encyclopedia)

Berkeley Software Distribution (BSD) is the name of the UNIX dialects distributed already in the 1970s from the University of California, Berkeley.

In its infancy AT&T Bell Laboratories permitted Berkeley and other universities to share the source code to their UNIX operating system. Berkeley used their software as a research base for a variety of investigations into operating system design throughout the 1970s and 1980s. Eventually the sum total of the systems that Berkeley students had developed from scratch for their research had replaced essentially every component of the original UNIX kernel, and in the early 1990s the full Berkeley source code was released publicly with a very generous license called the BSD License.

BSD pioneered many of the advances of modern computing. Berkeley's Unix was the first to include library support for the Internet protocol stacks, Berkeley sockets. By integrating sockets with the UNIX operating system file descriptors, users of their library found it almost as easy to read and write data across the network, as it was to put data on a disk. The AT&T laboratory eventually released their own STREAMS library which incorporated much of the same functionality in a software stack with better architectural layers, but the already widely distributed sockets library, together with the unfortunate omission of a function call for polling a set of open sockets (an equivalent of the select call in the Berkeley library), made it difficult to justify porting applications to the new API.

Like AT&T Unix, the BSD kernel is a monolithic kernel, meaning that device drivers in the kernel run in ring 0, the core of the operating system. Early versions of BSD were used to form Sun Microsystems' SunOS, founding the first wave of popular Unix workstations.

Other versions of UNIX that descend from BSD include FreeBSD, NetBSD, OpenBSD, 386BSD, DragonFlyBSD, and Apple's Darwin (and, hence, Mac OS X).

External link

• A timeline of BSD and Research UNIX can be found online at: ftp://ftp.freebsd.org/pub/FreeBSD/branches/-current/src/share/misc/bsd-family-tree

Further reading

• Chris Dibona, Mark Stone, Sam Ockman, Open Source (Organization), Brian Behlendorf and J. Scott Bradner, Opensources : Voices from the Open Source Revolution, O'Reilly & Associates, 1999, trade paperback, 272 pages, ISBN 1565925823; Online at http://www.oreilly.com/catalog/opensources/book/toc.html; Chapter on BSD - "Twenty Years of Berkeley Unix - From AT&T-Owned to Freely Redistributable"

  Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Berkeley Software Distribution."

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BSD license

(From Wikipedia, the free Encyclopedia)

BSD originally stood for "Berkeley Source Distribution". The BSD License was the license agreement that the BSD software (largely, a version of UNIX) was distributed under (and still is as of 2003). The owner of the original BSD distribution was the "Regents of the University of California". This is because BSD originally came from the University of California, Berkeley.

Versions of the current BSD template (and the older version with the advertising clause) are often used by other organizations. The BSD License does not prohibit the use of the material licensed in products for resale. A notable example of this is the use of BSD networking code in Microsoft products.

It is possible for something to be distributed with the BSD License and some other license to apply as well. This was in fact the case with very early versions of BSD Unix itself, which included proprietary material from AT&T.

As originally distributed the license had an extra clause, the so called advertising clause:

     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *    This product includes software developed by the University of
     *    California, Berkeley and its contributors.

The GNU project referred to it as the "obnoxious BSD advertising clause". Along with offending people, the clause caused a practical problem. People who made changes to the source code tended to want to have their names added to the acknowledgement. With large numbers of people working on a single project (or for many separate projects in a software distribution), the advertising clause quickly created large and unwieldy acknowledgements. Another practical problem was legal incompatibility with the terms of the GNU General Public License (which does not allow the addition of restrictions beyond those it already imposes), forcing a segregation of GNU and BSD software. On July 22, 1999, William Hoskins, the director of the office of technology licensing for Berkeley, revoked the clause. The document enacting that revocation is available at <ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change>. The original license is now sometimes called "BSD-old" or "4-clause BSD", with the revised license sometimes called "BSD-new", "revised BSD", or "3-clause BSD".

A 2-clause BSD-like license also exists; the clause deletes the third section, which prohibits use of the name of the copyright holder for endorsement purposes.

External links

• BSD licence template
• The BSD License Problem (GNU Project)
• Materials about the Unix System Laboratories v. BSD case
• Marshall Kirk McKusick, Twenty Years of Berkeley Unix: From AT&T-Owned to Freely Redistributable, in: Open Sources: Voices from the Open Source Revolution, O'Reilly 1999

  Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "BSD license."

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Abbreviations & Acronyms: BSD

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Commercial Usage: BSD

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Digital Photo Gallery: BSD
 

"Tolrance tux diving" by Julia Eisenberg Commentary: "Bsd tolerant tux diving for pringles."

Source: photographs selected by the editor, with permission from the photographers.

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Usage Frequency: BSD

Source: compiled by the editor from several corpora; see credits.

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Usage in Company Names: BSD

Source: compiled by the editor from Icon Group International, Inc.

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Expression: BSD

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Frequency of Internet Keywords: BSD

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Anagrams: BSD

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Alternative Orthography: BSD

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